Download Skeletal System

Skeletal System
1
Skeletal system
Skeletal system includes:
bones of the skeleton, cartilage and ligaments
Functions:
• Support (structural support of whole body)
• Storage of minerals (calcium)
• Storage of lipids (yellow marrow)
• Blood cell production (red marrow)
• Bone houses stem cells that produce RBCs, WBCs & platelets
• Protection
• Movement (bones and skeletal muscles provide movement)
• Bones act as levers that move when attached muscles contract
2
Axial Skeleton
Lies in the midline of the body
Bones of the axial skeleton:
Skull
Hyoid bone
The vertebral column
The thoracic cage
Middle ear bones
3
Vertebral Column (Spine)
• Supports rib cage
• Serves as a point of attachment for the
pelvic girdle
• Protects the spinal cord
• Cervical vertebrae – 7 bones of the neck
• Thoracic vertebrae – 12 bones of the torso
• Lumbar vertebrae – 5 bones of the lower back
• Sacrum – bone inferior to the lumbar vertebrae
• articulates with hip bones
• Coccyx
4
Abnormalities
Lordosis – exaggerated lumbar curvature
Kyphosis – increased roundness of the thoracic curvature
Scoliosis – abnormal lateral curvature that occurs most often in the thoracic
region
5
Joints (Articulations)
Three types of joints:
Fibrous
Cartilaginous
Synovial
Fibrous joints – fibrous connective tissue joins bone to bone
• typically immovable
• examples:
• sutures of cranium
• tooth in socket
6
Joints (Articulations)
Cartilaginous joints – bones are joined by fibrocartilage or hyaline cartilage
• typically slightly movable
• examples
• between adjacent bodies of vertebral bodies
• pubic symphysis of the pelvis
• between ribs and sternum
7
Joints (Articulations)
Synovial joints – bones do not touch each other
• bones are separated by a joint cavity
• typically freely movable
• but have to be stabilized via ligaments, muscles,
etc.
• examples:
8
Properties of Synovial Joints
synovial membrane – lines joint cavity → produces synovial fluid (lubricant)
ligaments (bone to bone connection) - support, strengthen joints
• sprain - ligaments with torn collagen fibers
tendons (bone to muscle connection) - help support joint
bursae - pockets of synovial fluid in CT (lined by synovial membrane)
• cushion areas where tendons or ligaments rub; “shock absorbers”
9
Movements Permitted By Synovial Joints
10
Joint Damage and Repair
• Cartilage and bone deteriorate with age
• cartilage can undergo calcification
• interferes with diffusion of nutrients/wastes through cartilage
• Joints can also become damaged by overuse or chronic inflammation
Arthritis – joint inflammation and destruction
Osteoarthritis – deterioration of the articular cartilage
Rheumatoid arthritis – synovial membrane inflamed & grows thicker
• autoimmune cause (immune system mistakenly attacks synovial
membrane)
11
MUSCLES
12
Smooth Muscle
• location: walls of hollow organs & blood vessels
• regulation of contraction: involuntary
• rhythmic contraction: yes, in digestive system muscles, in uterus during
childbirth
13
Cardiac Muscle
• location: heart
• regulation of contraction: involuntary, has its own pacemaker, but nervous
and endocrine system also influence heart rate
• rhythmic contraction: yes
intercalated discs - permit contractions to
spread quickly throughout the heart (gap
junctions)
14
Skeletal Muscle
• location: attached to bones, skin
• regulation of contraction: voluntary, but some skeletal muscles also
controlled unconsciously
• rhythmic contraction: no
fascia – connective tissue that separates
muscles from each other and the skin
15
Anatomy of Skeletal Muscle
Organization of Connective Tissues
1) Epimysium
epi = on
• surrounds entire muscle
• dense layer of collagen fibers
• separates muscles from
surrounding tissues/organs
• fibers continue as strong, fibrous
tendon (attached muscle to bone)
16
Anatomy of Skeletal Muscle
Organization of Connective Tissues
2) Perimysium
peri = around
• divides skeletal muscle into
compartments (fascicles)
fascicles = bundles of muscle fibers/cells)
17
Anatomy of Skeletal Muscle
Organization of Connective Tissues
3) Endomysium endo = inside
• surrounds individual skeletal
muscle cells (muscle fibers)
• loosely connects adjacent
muscle fibers
18
Term Break Down
●
●
●
●
●
●
●
●
Myasthenia Gravis
Levoscoliosis
Polymyositis
Spondylolisthesis
Rhabdomyosarcoma
Icteric
Osteoarthritis
Hemiparesis
●
●
●
●
●
●
●
●
Hemarthrosis
Encephalitis
Osteoporosis
Pruritic
Gangrenous
Necrotic
Oligodendroglioma
Ecchymosis
●
●
●
●
Cephalgia
Hematoma
Torticollis
Polymyalgia